PHY 1020 Chapter 6: Electricity and Magnetism !Current is measured by: A. Volts B. Calories C. Amps D. Watts E. Ohms !A Volt is a measure of A. Energy per electron B. Number of electrons per second C. Force on the electron D. density of electrons !Magnetism comes from A. magnetic models B. Moving quantum of light C. Quantization of charge D. Moving the electric charge !In a permanent magnet, the magnetism comes from A. the spin of the electrons B. The motion of the protons C. the high-voltage inside the Adam D. The electron avalanche !Magnetic monopoles A. are found at the ends of magnets B. Are produced by cosmic rates C. Are found in the earth's core D. Have never been found !Rail guns push the projectile using A. high-energy explosives B. Electric fields C. Magnetic field D. Protons !Tesla wanted to use a transformer to distribute electricity because A. it allowed there to be a powerplant in every neighborhood B. It made high-voltage less dangerous C. It decreased the current going through long wires to reduce the loss of electricity D. It was given strong support by Thomas Edison, who popularized it !You can demagnetize a natural magnet A. by placing it on a TV or computers B. By placing it in a very strong electric field C. By heating it above the Curie point D. None of the above !What discovery now allows for headphones to be small and light? A. dynamos B. Rare earth magnets, such as samarium cobalt C. Transformers D. maraging steel !Which of the following use or consist of permanent magnets? (choose all the apply) A. lodestones B. Transformers C. Compasses D. earphones !Theoretically, the earth should not have a permanent magnet in its core because A. it's interior is too hot B. The earth spins C. There is not enough iron D. Magnets do not occur naturally !The earth's magnetism comes from A. A dynamo in the core B. Permanent magnets in the core C. Iron in the crust D. Monopoles near (but not at) the north and south geographic poles. !The earth flips its magnetism, on average, Approximately A. once every 11 years B. Twice every million years C. Once every billion years D. Never (at least not yet) !The north in geographic pole of the earth A. is a south magnetic pole B. Has always had the same polarity C. Is exactly at the magnetic pole D. None of the above !Compasses point north because A. because the north star attacks them B. The earth has an electric charge C. There are electric currents in the iron core of the earth D. There are magnetic mono poles near the North Pole !Electricity will heat a wire if it has A. high-voltageB. High currant C. High-frequency D. DC rather than AC !Static electricity occurs when two surfaces rub against each other and A. protons flow from one to another B. Electrons flow from one to another C. Positrons flow from one to another D. Neutrons flow from one to another !Europe uses higher voltage in Hope's because A. Creates less heat in-home wiring B. Carries greater power C. Is less dangerous D. Works better for DC (used in Europe instead of AC) !Lights and TVs in your tent to flicker because Europe uses A. 220 volts - the US uses 110 volts B. 110 volts - the US uses 220 volts C. 50 volts - the US uses 60 hertz D. 60 volts - the US uses 50 hertz !When an object loses some electrons it A. has a negative charge B. Has a positive charge C. Has a low resistance D. Glows (e.g., lightbulb wire) !To get a spark, you normally need: A. high-voltage B. High current C. Low resistance D. Alternating current !A fuse is used in a house to prevent A. large power surges B. House wires from overheating C. illegal use of electricity D. Too much voltage entering the house E. Too much energy usage !The earth magnetic flips are used for A. creating new permanent magnets B. Proving the earth has a solid iron core C. Generating useful power D. Geologic dating !In a metal, Electrons A. are confined to a single Adam B. Always point in the same directionC. Can move freely D. Do not exist !The aspect of electricity that would make it most dangerous is high A. voltage B. Current C. Frequency D. Power !A certain kind of generator uses its own electricity to strengthen its magnetic field. Such a generator is called a A. superconductor B. Transformer C. samarium D. Dynamo !The original superconductors were cooled with A. liquid nitrogen B. Liquid helium C. freon refrigerators D. Hydrogens gas !Room temperature superconductors A. are used in advanced computers B. Are used to carry electric power C. Are used for strong magnets D. Have no practical applications !High-temperature superconductors operate at approximately A. room temperature B. 4 K (liquid helium temperature) C. -123 C (liquid nitrogen temperature) D. 2000 C !We use AC instead of DC because A. 110 volts AC is less dangerous than 110 Volts DC B. AC is cheaper than DC C. AC can use transformers D. DC can use transformers !Topsy was executed with AC A. to show the dangers of high footage B. Because DC would not have worked C. Because it was the only way to get high current D. AC delivers more power in DC Edison wanted A. A power plant on every city block B. High-voltage DC C. Alternating current D. To abolish the electric chair !The current through a flashlight blab is A. about 110 amps B. about 1.6 x 10-19 amp C. about one amp D. about 15 amps !A stereo speaker produces sound by the force A. of a magnetic field on electric current B. Of an electric field on an electric charge C. Of a magnetic field on an electric charge D. Of an electric field on a magnetic charge !The light from an ordinary lightbulb comes from the fact that A. the wire contains phosphor B. The wire is heated by electricity C. The high-voltage causes small sparks D. Electricity is a wave A Tesla coil is a kind of A. transformer B. Dynamo C. Radio transmitter D. Sensor for the Curie point !Submarines can be detected by their A. magnetism B. Electric charge C. Backscattered X-rays D. MRI Signal !At the Curie temperature A. molecular movement stops B. Fusion takes place in the sun C. Magnetism disappears D. Fission takes place in a bomb !The most electric power is generated by A. static electricity B. A wire moving through a magnetic field C. Moving a wire in a stronger electric field D. Chemical means (batteries or fuel cells) !What invention made it possible to charge low-voltage AC to high-voltage AC? A. Van de Graaff generator B. samarium-cobalt magnets C. Transformer D. Inverter !To reduce losses from resistance, Electric power lines
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